I have found that the finished quantity in system(dynamics 365 F&O) is more than actually after end the production order .I want to know how to handle this or adjust quantity and make inventory quantity and cost correctly.
If it's different after ending the production order, you'd have to do an inventory movement journal or something to get the quantity adjusted. There is no way to "unend" a production order after you've ended it.
If you need to get the inventory back in stock for the subcomponents, you could try a negative production order or a negative bill of materials journal. That might get things back where they should be and get rid of your extra inventory. Test it in a test environment first, of course.